Academic literature on the topic 'Geopolymer'
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Journal articles on the topic "Geopolymer"
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Pauzi, Ahmad Hafizi, Lukman Ismail, Ahmer Ali Siyal, Zakaria Man, and Khairun Azizi Azizli. "Experimental Study of Geopolymer Solidification Kinetics." Applied Mechanics and Materials 625 (September 2014): 127–30. http://dx.doi.org/10.4028/www.scientific.net/amm.625.127.
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Geopolymers are formed from silica and alumina oxides mixed with alkali hydroxide or alkali silicate. This paper presents the findings on the study of the solidification of fly ash geopolymer through setting time by varying alkaline activators, their concentrations and geopolymer curing temperature. This work focuses on the transformation of geopolymer from liquid paste to solid through Avrami’s Kinetic Theory. From the experimental results, alkaline activation with sodium silicate produced shortest time for geopolymer solidification as compared to KOH and NaOH. The increase in concentrations of alkaline solution and curing temperatures were found to reduce setting time for geopolymer’s solidification. From Avrami theory perspective, the growth forms of geopolymer in the geopolymerization process exhibit two and three dimensional structure with the presence of secondary nucleation.
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Guo, Xiao Lu, Hui Sheng Shi, Mao Song Lin, and Wen Jing Dong. "Effects of Calcium Contents in Class C Fly Ash Geopolymer." Advanced Materials Research 687 (April 2013): 508–13. http://dx.doi.org/10.4028/www.scientific.net/amr.687.508.
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Geopolymers with calcium contents were prepared from class C fly ash, metakaolin, and Ca(OH)2. Geopolymer products and ordinary cement hydration products were divided with gradient acid dissolution test. The effects of calcium in class C fly ash geopolymer were investigated through the calcium concentration of acid solution. In an appropriate alkali situation, most of the calcium will be dissolved from class C fly ash. Part of the calcium will react with silicate and aluminum to form geopolymeric gels as the presence of gismondine (zeolite). Part of calcium was hydrated to form calcium silicate hydrate(C-S-H), and the rest of calcium may be adsorbed within the geopolymeric binding structure to balance charge anion. The class C fly ash geopolymer is a composite system with the coexistence of geopolymeric and C-S-H gels.
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Lezzerini, Marco, Andrea Aquino, and Stefano Pagnotta. "Acid Resistance of Metakaolin-Based Geopolymers and Geopolymeric Mortars Reinforced with Coconut Fibers." Fibers 12, no. 5 (May 1, 2024): 40. http://dx.doi.org/10.3390/fib12050040.
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This paper investigates the durability of geopolymers and geopolymeric mortars made with metakaolin and alkaline activators, with and without a coconut fiber addition, after immersion for seven days into solutions of citric acid (1%, 2.5%, 5%, and 10%); hydrochloric acid (1%, 2.5%, 5%, and 10%); and sulfuric acid (1%, 2.5%, 5%, and 10%). The study focuses on mass changes, uniaxial compressive strength, flexural strength, and ultrasound pulse velocity measurements. X-ray diffraction and scanning electron microscopy are used to analyze the degradation products and microstructural changes. The aim is to assess the effect of acid exposure on the strength and stability of geopolymer materials and identify any protective effects of coconut fiber reinforcement. The samples are immersed in acid solutions of varying concentrations, and their mechanical properties are measured. The presence of coconut fibers slightly modifies the physical properties and the compressive strength, improving the mechanical flexural strength. Geopolymer and geopolymeric mortar materials experienced a weak decrease in strength when exposed to solutions of citric acid and a significant one when exposed to solutions of hydrochloric and sulfuric acids, attributed to depolymerization of the aluminosilicate binders. Brick waste geopolymeric mortars reinforced with coconut fibers showed the best performance in acid solutions with respect to geopolymers and quartz-rich sand geopolymeric mortars, suggesting a more stable cross-linked aluminosilicate geopolymer structure in this material.
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Malik, Muhammad Akbar, Manas Sarkar, Shilang Xu, and Qinghua Li. "Effect of PVA/SiO2 NPs Additive on the Structural, Durability, and Fire Resistance Properties of Geopolymers." Applied Sciences 9, no. 9 (May 13, 2019): 1953. http://dx.doi.org/10.3390/app9091953.
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This exertion introduces polyvinyl alcohol fiber/silica nanoparticles (poly vinyl alcohol (PVA)/SiO2 NPs) in the fly ash-based geopolymer at ambient curing temperature. The present study aims at investigating the structural properties (compressive, bond strength, fracture parameters (fracture toughness (KIc), crack mouth opening displacement (CMOD)), cyclic compression), durability (freeze-thaw), and fire resistivity of the newly developed PVA/SiO2 NPs mediated geopolymer. The outcomes suggest that geopolymers incorporated with 5% PVA fibers showed improved structural properties and durability as compared to other specimens. Investigation on the fire resistivity of the geopolymers exposed to different heating temperatures (400 °C, 600 °C, 800 °C), showed that geopolymers with PVA/SiO2 NPs significantly prevented the explosive concrete spalling. Microstructural studies confirmed that PVA fibers in the geopolymeric matrixes were well distributed and developed a fiber-bridging texture with improved performance. Addition of the nano-silica particles accelerated the heat evolution during the hydration process and the geopolymeric reaction (formation of sodium aluminosilicate N-A-S-H gel) at ambient curing environment.
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Le, Van Quang, Minch Quang Do, Minh Duc Hoang, Vo Thi Ha Quyen Pham, Thu Ha Bui, and Hoc Thang Nguyen. "Effect of Alkaline Activators to Engineering Properties of Geopolymer-Based Materials Synthesized from Red Mud." Key Engineering Materials 777 (August 2018): 508–12. http://dx.doi.org/10.4028/www.scientific.net/kem.777.508.
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Geopolymer is an inorganic polymer material formed from alumino-silicate structures. Geopolymer has many outstanding functions in comparison with ordinary materials such as high mechanical strength, high heat and chemical resistance, and lightweight property. The engineering properties of geopolymer-based materials depend on raw materials and synthesized conditions. In which, the aluminosilicate materials having high activity and consisting of many alkaline activators have the possibility of increasing pH in geopolymer paste. In the solution of paste, aluminosilicate compounds are solubilized and then react with alkali-activated ions to form geopolymeric networks. The geopolymer can be synthesized in many different conditions depending on factors of temperature, pressure, and curing conditions. In this study, red mud (RM) was used as the main alumino resource for geopolymerization process. RM is a solid waste residue being left from the mining process of bauxite ores with caustic soda for alumina production. Its disposal remains a global issue in terms of environmental concerns. Formation of RM-based geopolymer was affected by many factors, in which, the alkaline activators are the most important factor. This research was conducted with sodium hydroxide and sodium silicate solutions to elucidate the effect of alkaline activator ratio to the engineering properties of RM-based geopolymers. The results showed that the RM-based geopolymer used sodium silicate solution has more outstanding properties than RM-based geopolymer using sodium hydroxide solution.
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Zheng, Chuji, Jun Wang, Hengjuan Liu, Hota GangaRao, and Ruifeng Liang. "Characteristics and microstructures of the GFRP waste powder/GGBS-based geopolymer paste and concrete." REVIEWS ON ADVANCED MATERIALS SCIENCE 61, no. 1 (January 1, 2022): 117–37. http://dx.doi.org/10.1515/rams-2022-0005.
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Abstract A novel method is developed for reusing the waste glass fiber-reinforced polymer (GFRP) powder as a precursor in geopolymer production. Several activation parameters that affect the workability and strength gain of GFRP powder-based geopolymers are investigated. The results of an experimental study reveal that the early strength of GFRP powder-based geopolymer pastes develops slowly at ambient temperature. The highest compressive strength of GFRP powder-based geopolymer pastes is 7.13 MPa at an age of 28 days. The ratio of compressive strength to flexural strength of GFRP powder-based-geopolymers is lower than that of fly ash and ground granulated blast furnace slag (GGBS)-based geopolymers, indicating that the incorporation of GFRP powder can improve the geopolymer brittleness. GGBS is incorporated into geopolymer blends to accelerate the early activity of GFRP powder. The binary geopolymer pastes exhibit shorter setting times and higher mechanical strength values than those of single GFRP powder geopolymer pastes. The GGBS geopolymer concrete mixture with 30 wt% GFRP powder displayed the highest compressive strength and flexural strength values and was less brittle. The developed binary GFRP powder/GGBS-based geopolymers reduce the disadvantages of single GFRP powder or GGBS geopolymers, and thus, offer high potential as a building construction material.
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Al Bakri, Abdullah Mohd Mustafa, J. Liyana, Md Tahir Muhammad Faheem, Hussin Kamarudin, A. R. Razak, Zarina Yahya, and A. Alida. "Effect on Strength and Hardness of Clay Ceramic Substrate after Treatment Using Koalin Based Geopolymer Glaze." Key Engineering Materials 594-595 (December 2013): 575–80. http://dx.doi.org/10.4028/www.scientific.net/kem.594-595.575.
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Geopolymerization is an alternative for ceramic industry by using clay based material such as kaolin or calcined kaolin geopolymer. Geopolymer paste is initially produced by alkaline activation of calcined kaolin with NaOH and Na2SiO3solution), dried at 80oC for 4 hours, pulverized and sieved to fixed particle size powder. The parameters involved in this processing route (alkali concentration, kaolin or calcined kaolin to activator ratio, alkali activator ratio and heating conditions) are investigated. Geopolymeric powder is added with water to produce slurry to be coated on the surface of clay ceramic. It undergoes heat treatment at high temperature to produce glaze on the surface. Flexural strength and hardness analysis are studied. Result evidences the processing show of incresing strength value between 8-10% after treatment with geopolymer glaze and also the Vickers hardness values of geopolymers improved.
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Asprogerakas, A., Aristea Koutelia, Glykeria Kakali, and Sotirios Tsivilis. "Durability of Fly Ash Geopolymer Mortars in Corrosive Environments, Compared to that of Cement Mortars." Advances in Science and Technology 92 (October 2014): 84–89. http://dx.doi.org/10.4028/www.scientific.net/ast.92.84.
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In the present paper the durability of fly ash geopolymer mortars compared to that of cement mortars is investigated. Geopolymers can improve the ecological image of building materials, especially when their production is based on industrial by-products such as fly ash. Three series of fly ash based geopolymer mortars were prepared using calcareous sand to fly ash ratio (S/FA) varying from 0.5 to 2. In addition, cement mortar specimens were prepared using cement CEM I 42.5 N and CEM II 32.5 N. Durability of geopolymer and cement mortars was evaluated by means of compressive strength development, acid resistance, chloride diffusion and sulfate resistance. It was found that fly ash can be effectively used to produce geopolymer mortars with calcareous sand. Geopolymers exhibit competitive compressive strength compared to that of cement mortars. Geopolymer mortars develop their maximum compressive strength a few days after their casting. Geopolymer and cement mortars exhibit satisfactory resistance to sulphate attack. Cement mortars, generally, show better behaviour (compared to geopolymers) in chloride diffusion. Finally, geopolymers indicate improved performance against acid attack, compared to that of cement mortars.
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Lin, Wei-Ting, Kae-Long Lin, Kinga Korniejenko, and Lukáš Fiala. "Comparative Analysis Between Fly Ash Geopolymer and Reactive Ultra-Fine Fly Ash Geopolymer." International Journal of Engineering and Technology Innovation 11, no. 3 (May 5, 2021): 161–70. http://dx.doi.org/10.46604/ijeti.2021.7129.
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This study investigates novel geopolymers by combining Reactive Ultra-fine Fly Ash (RUFA) with 4M sodium hydroxide as an alkali activator. Comparing with general fly ash geopolymers, RUFA geopolymer pastes are characterized in terms of compressive strength, microstructure, and crystalline phases. The RUFA geopolymer is successfully obtained as alumina-silicate bonding materials with the same properties as the general fly ash-based geopolymer. The high compressive strength of the RUFA-based geopolymer samples (13.33 MPa) can be attributed primarily to Ca-based alumino-silicate hydration products and Na-based alumino-silicate complexes. This research presents an innovative application for geopolymers using RUFA. In the follow-up study, the influence of synthesis and concentration of alkali activator can be considered in RUFA-based geopolymers.
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Pathak, Arvind, Arpana Ranjit, and Bijaya Dhakal. "Geopolymerization Behaviour of Red and White Clays." Journal of Nepal Chemical Society 43, no. 1 (August 30, 2022): 27–34. http://dx.doi.org/10.3126/jncs.v43i1.46997.
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Construction is one of the most important activities increasing the demand for Portland cement resulting significant amount of CO2 emission, natural resources degradation, and a high amount of energy consumption. The use of geopolymer has been studied as a potential substitute for Portland cement. Geopolymers are environmentally-friendly binding materials that are produced by the polymerization of alumino-silicates in presence of alkali polysilicates forming Si-O-Al bonds, which are used for several building applications. In this study, red and white clays which contain solid alumino-silicate have shown reactive in presence of an alkaline activator. The addition of lime has shown improvement in the mechanical and physical properties of the geopolymer products. The FTIR analysis and SEM images of the product have shown the formation of aluminosilicate gel in the geopolymeric product. The maximum compressive strength of the geopolymer products RCW and RWL were achieved to be 15.91 and 20.30 MPa, respectively. Such geopolymer products are in good agreement with cementitious products and can be used in building applications.
Dissertations / Theses on the topic "Geopolymer"
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Williams, Ross Peter. "Optimising Geopolymer Formation." Thesis, Curtin University, 2015. http://hdl.handle.net/20.500.11937/2359.
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Geopolymers are versatile materials, often made with ash from coal Power Stations. Applications include low green-house-gas emission cement, fireproof barriers and many more. This thesis furthered the understanding of geopolymer formulation by: • Demonstrating novel methods for mixture design and determining the degree of reaction during and after curing. • Analysing the role of formulation on cost and green-house-gas emission. • Developing a new material that can be used for structural neutron shielding.
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Bai, Chengying. "Highly porous geopolymer components." Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3427257.
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The geopolymers, semi-crystalline three-dimensional silico-aluminate inorganic polymers, have attracted increasing attention from a wide range of scientific interests. The topic of this study deals with the synthesis, the characterization and the potential applications of porous geopolymers (PGs) or geopolymer foams (GFs, total porosity > 70 vol%), realized through different processing routes. Firstly, the processes are divided into five categories: (i) direct foaming, (ii) replica method, (iii) sacrificial template, (iv) the 3D printing, and (v) others. The microstructure, porosity, and properties of porous geopolymers also compared and discussed. Secondly, K-based porous geopolymers were produced by direct foaming using hydrogen peroxide as chemical pore-forming agent (PFA) combined with three types of stabilizing agent (SA, egg white, Tween 80, vegetable oils), and by direct foaming plus reactive emulsion templating. Furthermore, open-celled phosphate-based porous geopolymers were obtained by a simple direct foaming method (using Triton X-100 as physical pore-forming agent). The porosity, pore morphology, high temperature performance, adsorption, mechanical, and insulating properties of PGs were investigated. High strength PGs with tailored porosity and controlled macro-porous structure were fabricated by different processes. The results suggest that the porous geopolymers are promising low-cost highly porous candidates for potential applications such as catalyst or membrane supports (high open porosity and high strength), adsorption (high removal efficiency and adsorption capacity with high open porosity) and insulating (low thermal conductivity, high porosity, and acceptable strength) materials.I geopolimeri, polimeri inorganici silicoalluminati tridimensionali semi-cristallini, hanno attirato crescente attenzione da una vasta gamma di interessi scientifici. L'argomento di questo studio riguarda la sintesi, la caratterizzazione e le potenziali applicazioni di geopolimeri porosi (PG) o schiume di geopolimeri (GF, porosità totale> 70% vol), realizzati attraverso diversi percorsi di lavorazione. In primo luogo, i processi sono suddivisi in cinque categorie: (i) schiumatura diretta, (ii) metodo di replica, (iii) modello sacrificale, (iv) stampa 3D e (v) altri. Anche la microstruttura, la porosità e le proprietà dei geopolimeri porosi sono state confrontate e discusse. In secondo luogo, i geopolimeri porosi basati su K sono stati prodotti mediante schiumatura diretta utilizzando perossido di idrogeno come agente chimico di formazione dei pori (PFA) combinato con tre tipi di agente stabilizzante (SA, bianco d'uovo, Tween 80, oli vegetali) e mediante schiumatura diretta più reattivo emulsione che modella. Inoltre, geopolimeri porosi a base di fosfato a cellule aperte sono stati ottenuti con un semplice metodo di schiumatura diretta (usando Triton X-100 come agente fisico di formazione dei pori). Sono state studiate la porosità, la morfologia dei pori, le prestazioni ad alte temperature, l'adsorbimento, le proprietà meccaniche e isolanti delle PG. I PG ad alta resistenza con porosità adattata e struttura macroporosa controllata sono stati fabbricati con diversi processi. I risultati suggeriscono che i geopolimeri porosi promettono candidati altamente porosi a basso costo per potenziali applicazioni come catalizzatori o supporti a membrana (elevata porosità aperta e alta resistenza), adsorbimento (alta efficienza di rimozione e capacità di adsorbimento con elevata porosità aperta) e isolanti (basso materiali di conducibilità termica, elevata porosità e resistenza accettabile).
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Sundqvist, Martin. "GEOPOLYMERS WITH GREEN LIQUOR DREGS : An investigation of the possibility tomanufacture a geopolymer based on residual streams." Thesis, Umeå universitet, Kemiska institutionen, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-185528.
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The pulp and paper industry make up a large part of the Swedish industry and is alsogrowing worldwide. With its growth, the amounts of residuals that are produced alsoincrease. The estimated annual global amount of residuals generated from pulp millsexceeds 1 million tons. The residuals include fly ash (FA) and green liquor dregs(GLD), which can cause harm to the environment as well as to the human health ifnot taken care of properly. Therefore, new, sustainable uses for these residual streamsare in strong need to be found. The construction sector is one of the most energy-intensive and CO2-emitting sectorssince ordinary Portland cement (OPC) is one of the most manufactured materials inthe world and causes large amounts of CO2 emissions when produced. Research hasfocused on reducing the CO2 generated by OPC. One approach is to include FA andGLD in a so-called geopolymer, which is a cementitious material formed when aninorganic material rich in aluminium (Al) and silicon (Si) reacts with an alkalineactivator such as sodium hydroxide (NaOH). A strong geopolymer including FA andGLD would not only create a use for these residuals, but it would also be a lessenergy craving alternative to concrete. Using FA and GLD from the Metsä Board pulp mill in Husum in various proportions,this study aimed for creating a geopolymer that is suitable as a construction material.The composition of the geopolymer blends differed depending on the proportions ofGLD and FA added, as well as regarding the water contents of the blends, and thequantity of alkaline activator solution added. The compositions also varied regardingthe addition of kaolin, an additional aluminosilicate source. Lignosulfonate, a ligninbasedproduct from the sulfite pulping industry was also evaluated as an additive dueto its water-reducing properties when used in concrete. The geopolymers wereevaluated in terms of blend workability and by uniaxial compressive strength (UCS)tests after 7 and 28 days of curing. The strongest geopolymer, in which GLD constituted 20 wt.% of the dry components(sand and alkaline chemicals excluded), endured a pressure of 2.3 MPa after 28 daysof curing. Increasing the water content made the geopolymer blend more workable,but also resulted in a UCS decrease of the geopolymer. Addition of cement to themixture and an increased quantity of alkaline activator solution both resulted in alower UCS as well. Compared to cement mortar (20 MPa at the 7th curing day) andliterature values of other geopolymers, the strengths of the manufacturedgeopolymers were low overall (0.4–1.4 MPa at the 7th curing day). One reason for thelow UCS could be the use of kaolin instead of a more reactive aluminosilicate source.Moreover, the FA showed to have low Si and Al contents, which can affect thegeopolymer strength. Further investigations are needed to develop a strongergeopolymer.
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Suwan, Teewara. "Development of self-cured geopolymer cement." Thesis, Brunel University, 2016. http://bura.brunel.ac.uk/handle/2438/12975.
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To support the concept of environmentally friendly materials and sustainable development, the low-carbon cementitious materials have been extensively studied to reduce amount of CO2 emission to the atmosphere. One of the efforts is to promote alternative cementitious binders by utilizing abundant alumina-silicate wastes from the industrial sectors (e.g. fly ash or furnace slag), among which “Geopolymer (GP) cement” has received most attention as it can perform a wide variety of behaviours, in addition to cost reduction and less environmental impacts. The most common geopolymer production, fly ash-based, gained some strength with very slow rate at ambient temperature, while the strength is evidently improved when cured in high (above room) temperature, e.g. over 40°C. The major challenge is to step over the limitation of heat curing process and inconvenience in practice. In this study, the testing schemes of (i) GP manufacturing in various processes, (ii) inclusion of ordinary Portland cement (OPC) in GP mixture, called GeoPC and (iii) GeoPC manufactured with dry-mixing method, have been intensively investigated through mechanical testing (Setting time, Compressive strength and Internal heat measurement) and mechanism analysis (XRD, FTIR, SEM and EDXA) in order to develop the geopolymers, achieving reasonable strength without external sources of heat curing. It is found that the proposed (dry) mixing process could have generated intensive heat liberation which was observed as a comparable factor to heat curing from any other external sources, enhancing the curing regime of the mixture. The additional calcium content in the developed GeoPC system not only resulted in an improvement of an early strength by the extra precipitation of calcium compounds (C,N-A-S-H), but also provided a latent heat from the reaction of its high potential energy compounds (e.g. OPC or alkaline activators). The developments from these approaches could lead to geopolymer production to achieve reasonable strength in ambient curing temperature known as “Self-cured geopolymer cement”, without external heat, and hence provide construction industry viable technologies of applying geopolymers in on-site and off-site construction.
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Adesanya, E. (Elijah). "Fiber-reinforced mineral wool geopolymer composites." Master's thesis, University of Oulu, 2015. http://urn.fi/URN:NBN:fi:oulu-201506271885.
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This thesis investigates the utilization of mineral wool (glasswool and rockwool) as precursor with metakaolin in geopolymerization. In 2015, mineral wool waste in Europe is estimated to be 2.4 metric tonnes, and it is currently landfilled. The utilization of this waste in geopolymer composites is one of the motivation towards this study. Indeed, addition of these mineral wools to metakaolin-based geopolymers matrices showed significant improvement in the mechanical properties.
The literature section of this thesis describes the previous knowledge on geopolymerization, the materials used in geopolymer and the factors affecting the mechanical strength. In the experimental part, the first goal was to achieve mix composition with highest mechanical strength and also a workable paste of geopolymers. This was done with the following factors held constant: SiO₂/Al₂O₃ = 3.8 and Na₂O/Al₂O₃ = 1, and varying the following: H₂O/Na₂O from 10 to 13, SiO₂/Na₂O from 3.21 to 4.02, mineral wool/metakaolin mass ratio from 0–1, and water/binder (w/b) mass ratio from 0.42 to 0.55.
The different mix compositions was calculated at varying substitution (10%, 20%, 30%, 40% and 50%) of metakaolin with mineral wool using both glasswool and rockwool in different matrices to determine the effect of mineral wool substitution on the properties of the geopolymer. Mechanical strength tests were done to determine the effects of mineral wool addition in the geopolymer. Results from the test shows maximum compressive strength of 33 MPa when 20% of the metakaolin was substituted with mineral wool. Further substitution was observed to reduce the mechanical properties of the geopolymer.
Also, optimization of glasswool and rockwool in different compositional mixes was done to select a particular mineral wool to be used further in the course of the study. Glasswool precursor with metakaolin showed better compressive strength using the chosen SiO₂/Al₂O₃ and Na₂O/Al₂O₃-ratios, compared to rockwool and was continued as the co-binder with metakaolin during reinforcement with fibres. Additionally, during the investigation the matrices were cured at various temperatures (50, 60, 80 and 100 °C). Results showed best mechanical strength was achieved when the geopolymer matrices were cured at 50 °C. XRD and TGA where used to characterize the behaviour of the raw materials and geopolymer samples and to verify geopolymer formations and its thermal stability respectively.
Geopolymers in general during testing experiences brittle failure, this limitation can be corrected using fibre reinforcement. Geopolymer composites with glass, carbon and cotton/polyester fibres were investigated using a simple layering method. Data from these preliminary tests showed that cotton/polyester blend fibre exhibited better ductility and flexural strength than glass and carbon fibre.
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Lo, Xin Yin. "Analysis and reproduction of geopolymer concrete." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/127289.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, May, 2020Cataloged from the official PDF of thesis.
Includes bibliographical references (page 36).
Geopolymers are inorganic polymers based on aluminosilicates that are produced from synthesizing pozzolanic compounds or aluminosilicate source materials with highly alkaline solutions. Geopolymer concrete is a stronger, more durable and more environmentally friendly alternative to ordinary Portland cement (OPC) concrete. Based on Joseph Davidovits' recipe for geopolymer concrete, we varied the ratios of the materials in an attempt to produce the ideal formula for the concrete that withstands maximum compressive strength. Through our iterations, we found the optimum texture was produced when the amount of sodium carbonate and lime are proportionally increased relative to the rest of the materials.
by Xin Yin Lo.
M. Eng.
M.Eng. Massachusetts Institute of Technology, Department of Civil and Environmental Engineering
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Matenda, Amanda Zaina. "GEOPOLYMER CONCRETE PRODUCTION USING COAL ASH." OpenSIUC, 2015. https://opensiuc.lib.siu.edu/theses/1654.
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Coal powered power plants account for more than 40 percent of the electricity production of the United States. The combustion of coal results in a large number of solid waste materials, or coal combustion byproducts (CCBs). These waste materials are stored in landfill or ponds. The construction industry is heavily reliant on concrete which is used to make the building blocks for any type of structures, bricks. Concrete is a composite material made of a binder and coarse and fine aggregate. The most widely used binder in concrete production is Ordinary Portland Cement (OPC). Since cement manufacture is costly and environmentally damaging, research has increased in recent years to find a more readily available binder. This study aims at investigating the properties of Illinois fly ash as a binder in the production of geopolymer concrete. Geopolymer concrete is an innovative material made by using Alumina and Silica rich materials of geological origins as a binder as well as an alkali activated solution. Sodium Silicate and Sodium Hydroxide were used to make the activator solution of two different ratios. Geopolymer Concrete with a ratio of 1:1 of Sodium Silicate to Sodium Hydroxide reached a compressive strength above 6000 psi while samples made with a ratio of 1:2 reached a compressive strength above 4000 psi. This environmentally-friendly, green concrete was also found to have a cost comparable to conventional concrete.
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Shadnia, Rasoul, and Rasoul Shadnia. "Green Geopolymer with Incorporated PCM for Energy Saving in Buildings." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/622931.
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This research studies the green geopolymer incorporated with phase change material (PCM) for energy saving in buildings. First class F fly ash (FA) based-geopolymer binder was studied. In order to improve the mechanical properties, low calcium slag (SG) was added to the FA to produce geopolymer. The effect of different factors including SG content (at different relative amounts FA/SG = 0/100, 25/75, 50/50, 75/25 and 100/0), NaOH solution at different concentrations (7.5, 10 and 15 M), various curing times (1, 2, 4, 7, 14 and 28 days) and curing temperatures (25 (ambient), 45, 60, 75 and 90°C) was investigated. The unit weight and uniaxial compressive strength (UCS) of the geopolymer specimens were measured. Scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) and X-ray diffraction (XRD) were also performed to characterize the microstructure and phase composition of the geopolymer specimens. The results show that the incorporation of SG not only improves the strength of the geopolymer specimens but also decreases the initial water content and thus the NaOH consumption at the same NaOH concentration required for geopolymer production. In addition, the inclusion of SG increases the unit weight of the geopolymer specimens, simply because SG has a much greater specific gravity than FA. The results also show that the strength of the FA/SG-based geopolymer develops rapidly within only 2 days and no obvious gain of the strength after 7 days. The optimum curing temperature (the curing temperature at which the maximum UCS is obtained) at a FA/SG ratio of 50/50 is around 75°C. Second, FA-based geopolymer concrete was synthesized and the effect of different factors including sodium silicate to sodium hydroxide (SS/SH) ratio, aggregate shape, water to fly ash (W/FA) ratio, curing time, water exposure and PCM inclusion on the compressive strength of the geopolymer concrete specimens cured at different ambient temperatures was studied. The results show that the UCS of the specimens increases with higher SS/SH and W/FA ratios up to a certain level and then starts to decrease at higher ratios. The results also indicate that a major portion of the strength of the specimens cured at ambient temperatures develops within the first four weeks. In addition the strength of the FA-based geopolymer concrete is slightly decreased with water exposure and PCM incorporation. Third, the mechanical and thermal properties of geopolymer mortar synthesized with FA and different amount of PCM were studied and the effect of incorporated PCM on the unit weight and UCS of geopolymer mortar was evaluated. SEM imaging was performed to identify the change of micro structure of the geopolymer mortar after incorporation of PCM. The thermal properties of the geopolymer mortar containing different amount of PCM were also characterized using differential scanning calorimetry (DSC) analysis. In addition model tests were performed using small cubicles built with geopolymer mortar slabs containing different amount of PCM to evaluate the effectiveness of geopolymer mortar wall with incorporated PCM in controlling the heat flow and internal temperature. The results indicate that both the unit weight and UCS of the geopolymer mortar decrease slightly after PCM is incorporated, mainly due to the small unit weight and low strength and stiffness of the PCM, respectively. However, the compressive strength of geopolymer mortar containing up to 20% PCM is still sufficiently high for applications in buildings. The results also show that the incorporation of PCM leads to substantial increase of heat capacity and decrease of thermal conductivity of the geopolymer mortar and is very effective in decreasing the temperature inside the cubicles. Finally, a numerical study on the thermal performance of geopolymer with incorporated PCM was carried out. In order to simulate the heat transfer through geopolymer containing PCM, a simplified method was first presented. The influence of phase transition was linked to the energy balance equation through variable specific heat capacity of the PCM-geopolymer. The thermal properties of the geopolymer containing PCM for the numerical analysis were determined using DSC and guarded heat flow (GHF) tests. The simplified method was validated based on the good agreement between the numerical and experimental results. With the validated model, the effect of various factors including the specific heat capacity, thermal conductivity and wall thickness on the thermal performance of PCM-geopolymer walls was studied. Then a modified numerical method was proposed for simulating the whole thermal transfer processes and the simulation results were used to conduct the economic evaluation of PCM-geopolymer walls for energy savings in buildings.
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Hardjito, Djwantoro. "Studies of fly ash-based geopolymer concrete." Thesis, Curtin University, 2005. http://hdl.handle.net/20.500.11937/634.
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The use of Portland cement in concrete construction is under critical review due to high amount of carbon dioxide gas released to the atmosphere during the production of cement. In recent years, attempts to increase the utilization of fly ash to partially replace the use of Portland cement in concrete are gathering momentum. Most of this by-product material is currently dumped in landfills, creating a threat to the environment. Geopolymer concrete is a ‘new’ material that does not need the presence of Portland cement as a binder. Instead, the source of materials such as fly ash, that are rich in Silicon (Si) and Aluminium (Al), are activated by alkaline liquids to produce the binder. Hence concrete with no Portland cement. This thesis reports the details of development of the process of making fly ash-based geopolymer concrete. Due to the lack of knowledge and know-how of making of fly ashbased geopolymer concrete in the published literature, this study adopted a rigorous trial and error process to develop the technology of making, and to identify the salient parameters affecting the properties of fresh and hardened concrete. As far as possible, the technology that is currently in use to manufacture and testing of ordinary Portland cement concrete were used. Fly ash was chosen as the basic material to be activated by the geopolimerization process to be the concrete binder, to totally replace the use of Portland cement. The binder is the only difference to the ordinary Portland cement concrete. To activate the Silicon and Aluminium content in fly ash, a combination of sodium hydroxide solution and sodium silicate solution was used. Manufacturing process comprising material preparation, mixing, placing, compaction and curing is reported in the thesis.Napthalene-based superplasticiser was found to be ii useful to improve the workability of fresh fly ash-based geopolymer concrete, as well as the addition of extra water. The main parameters affecting the compressive strength of hardened fly ash-based geopolymer concrete are the curing temperature and curing time, the molar H2O-to-Na2O ratio, and mixing time. Fresh fly ash-based geopolymer concrete has been able to remain workable up to at least 120 minutes without any sign of setting and without any degradation in the compressive strength. Providing a rest period for fresh concrete after casting before the start of curing up to five days increased the compressive strength of hardened concrete. The elastic properties of hardened fly ash-based geopolymer concrete, i,e. the modulus of elasticity, the Poisson’s ratio, and the indirect tensile strength, are similar to those of ordinary Portland cement concrete. The stress-strain relations of fly ash-based geopolymer concrete fit well with the expression developed for ordinary Portland cement concrete.
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Hardjito, Djwantoro. "Studies of fly ash-based geopolymer concrete." Curtin University of Technology, Dept. of Civil Engineering, 2005. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=18580.
Full textAbstract:
The use of Portland cement in concrete construction is under critical review due to high amount of carbon dioxide gas released to the atmosphere during the production of cement. In recent years, attempts to increase the utilization of fly ash to partially replace the use of Portland cement in concrete are gathering momentum. Most of this by-product material is currently dumped in landfills, creating a threat to the environment. Geopolymer concrete is a ‘new’ material that does not need the presence of Portland cement as a binder. Instead, the source of materials such as fly ash, that are rich in Silicon (Si) and Aluminium (Al), are activated by alkaline liquids to produce the binder. Hence concrete with no Portland cement. This thesis reports the details of development of the process of making fly ash-based geopolymer concrete. Due to the lack of knowledge and know-how of making of fly ashbased geopolymer concrete in the published literature, this study adopted a rigorous trial and error process to develop the technology of making, and to identify the salient parameters affecting the properties of fresh and hardened concrete. As far as possible, the technology that is currently in use to manufacture and testing of ordinary Portland cement concrete were used. Fly ash was chosen as the basic material to be activated by the geopolimerization process to be the concrete binder, to totally replace the use of Portland cement. The binder is the only difference to the ordinary Portland cement concrete. To activate the Silicon and Aluminium content in fly ash, a combination of sodium hydroxide solution and sodium silicate solution was used. Manufacturing process comprising material preparation, mixing, placing, compaction and curing is reported in the thesis.Napthalene-based superplasticiser was found to be ii useful to improve the workability of fresh fly ash-based geopolymer concrete, as well as the addition of extra water. The main parameters affecting the compressive strength of hardened fly ash-based geopolymer concrete are the curing temperature and curing time, the molar H2O-to-Na2O ratio, and mixing time. Fresh fly ash-based geopolymer concrete has been able to remain workable up to at least 120 minutes without any sign of setting and without any degradation in the compressive strength. Providing a rest period for fresh concrete after casting before the start of curing up to five days increased the compressive strength of hardened concrete. The elastic properties of hardened fly ash-based geopolymer concrete, i,e. the modulus of elasticity, the Poisson’s ratio, and the indirect tensile strength, are similar to those of ordinary Portland cement concrete. The stress-strain relations of fly ash-based geopolymer concrete fit well with the expression developed for ordinary Portland cement concrete.
Books on the topic "Geopolymer"
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Jia, Dechang, Peigang He, Meirong Wang, and Shu Yan. Geopolymer and Geopolymer Matrix Composites. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-9536-3.
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Hicks, James K. Geopolymer Binder Systems. Edited by Leslie Struble. 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959: ASTM International, 2013. http://dx.doi.org/10.1520/stp1566-eb.
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ASTM International Committee C01 on Cement and ASTM International Committee C09 on Concrete and Concrete Aggregates, eds. Geopolymer binder systems. West Conshohocken, PA: ASTM International, 2013.
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Low, It-Meng, Thamer Alomayri, and Hasan Assaedi. Cotton and Flax Fibre-Reinforced Geopolymer Composites. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-2281-6.
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Brito, Manuel, Eldon Case, Waltraud M. Kriven, Jonathan Salem, and Dongming Zhu, eds. Developments in Porous, Biological and Geopolymer Ceramics. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2007. http://dx.doi.org/10.1002/9780470339749.
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Malaysia) Malaysia-Indonesia Geopolymer Symposium (2014 Kuala Lumpur. Geopolymer and Green Technology Materials: Selected, peer reviewed papers from the 2014 Malaysia-Indonesia Geopolymer Symposium (MIGS 2014), May 11-12, 2014, Kuala Lumpur, Malaysia. Pfaffikon, Switzerland: TTP, Trans Tech Publications Ltd, 2015.
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Vizureanu, Petrica, Mohd Mustafa Al Bakri Abdullah, Rafiza Abdul Razak, Dumitru Doru Burduhos-Nergis, Liew Yun-Ming, and Andrei Victor Sandu. Geopolymers. Boca Raton: CRC Press, 2023. http://dx.doi.org/10.1201/9781003390190.
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Vickers, Les, Arie van Riessen, and William D. A. Rickard. Fire-Resistant Geopolymers. Singapore: Springer Singapore, 2015. http://dx.doi.org/10.1007/978-981-287-311-8.
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Yan, Dongming, Shikun Chen, and Yi Liu. Metakaolin-Based Geopolymers. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-97-0652-5.
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Rashad, Alaa M. Silica Fume in Geopolymers. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-33219-7.
Full textBook chapters on the topic "Geopolymer"
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Li, Yongxiang, Lijuan Yang, Xiao Li, Yongfei Li, Qiang Zhang, and Shoude Pang. "Mechanical Properties and Micromechanism of Geopolymers to Replace Cement Stabilized Crushed Stone." In Lecture Notes in Civil Engineering, 43–58. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-1748-8_4.
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AbstractIn order to realize the resource utilization of solid waste, the principle of alkali excitation is used to prepare geopolymers with fly ash, mineral powder and wet carbide slag as the main materials to replace part of the cement as the cementing material for the pavement base. Geopolymer-stabilized crushed stone was prepared by compounding cement and aggregate with geopolymer, and the unconfined compression strength, indirect tensile strength, compression rebound modulus, scour resistance and microscopic X-ray diffraction (XRD) and scanning electron microscopy (SEM) tests were carried out to study the effect of the change of geopolymer content on the mechanical properties of geopolymer-stabilized crushed stone and its mechanism. The test results show that when adding 30% geopolymer, the mechanical properties similar to those of cement can be obtained to a certain extent. XRD and SEM analysis showed that the geopolymer provided appropriate amount of silico-alumina and calcareous components to form calcium silicate hydrate (C–S–H) and calcium silicate (aluminum) hydrate (C–(A) –S–H) condensation. The glue can form a dense structure and increase the strength of the mixture.
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Prochoń, Piotr, Tomasz Piotrowski, Luc Courard, and Zengfeng Zhao. "The Effects of Calcium and Phosphate Compounds on the Mechanical and Microstructural Properties of Fly Ash Geopolymer Mortars." In Springer Proceedings in Materials, 230–38. Cham: Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-72955-3_23.
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AbstractPhosphorus and calcium compounds are present in the chemical composition of byproducts from coal and biomass combustion. They may have an influence on the microstructure and the mechanical properties through the specific bonds in polymeric aluminosilicates - geopolymers. Results proved that the 5% of CaO added to high-silica fly ash geopolymer increases material density and mechanical properties. Phosphate compounds available in the biomass fly ash have a negative effect on geopolymer mortars by increasing porosity and decreasing their compressive strength.
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Law, D. W., C. Gunasekara, and S. Setunge. "Use of Brown Coal Ash as a Replacement of Cement in Concrete Masonry Bricks." In Lecture Notes in Civil Engineering, 23–25. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-3330-3_4.
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AbstractPortland cement production is not regarded as environmentally friendly, because of its associated high carbon emissions, which are responsible for 5% of global emissions. An alternative is to substitute fly ash for Portland cement. Australia has an abundance of brown coal fly ash, as it is the main source of primary energy in the State of Victoria. Currently, the majority of this material is stored in landfills and currently there is no commercial use for it in the cement industry because brown coal fly ash cannot be used as a direct replacement material for Portland cement due to the high sulfur and calcium content and low aluminosilicate content. However, the potential exists to use brown coal fly ash as a geopolymeric material, but there remains a significant amount of research needed to be conducted. One possible application is the production of geopolymer concrete bricks. A research project was undertaken to investigate the use of brown coal fly ash from Latrobe Valley power stations in the manufacture of geopolymer masonry bricks. The research developed a detailed understanding of the fundamental chemistry behind the activation of the brown coal fly ash and the reaction mechanisms involved to enable the development of brown coal fly ash geopolymer concrete bricks. The research identified suitable manufacturing techniques to investigate relationships between compressive strength and processing parameters and to understand the reaction kinetics and microstructural developments. The first phase of the research determined the physical, chemical, and mineralogical properties of the Loy Yang and Yallourn fly ash samples to produce a 100% fly ash-based geopolymer mortar. Optimization of the Loy Yang and Yallourn geopolymer mortars was conducted to identify the chemical properties that were influential in the production of satisfactory geopolymer strength. The Loy Yang mortars were able to produce characteristic compressive strengths acceptable in load-bearing bricks (15 MPa), whereas the Yallourn mortars produced characteristic compressive strengths only acceptable as non-load-bearing bricks (5 MPa). The second phase of the research transposed the optimal geopolymer mortar mix designs into optimal geopolymer concrete mix designs while merging the mix design with the optimal Adbri Masonry (commercial partner) concrete brick mix design. The reference mix designs allowed for optimization of both the Loy Yang and Yallourn geopolymer concrete mix designs, with the Loy Yang mix requiring increased water content because the original mix design was deemed to be too dry. The key factors that influenced the compressive strength of the geopolymer mortars and concrete were identified. The amorphous content was considered a vital aspect during the initial reaction process of the fly ash geopolymers. The amount of unburnt carbon content contained in the fly ash can hinder the reactive process, and ultimately, the compressive strength because unburnt carbon can absorb the activating solution, thus reducing the particle to liquid interaction ratio in conjunction with lowering workability. Also, fly ash with a higher surface area showed lower flowability than fly ash with a smaller surface area. It was identified that higher quantity of fly ash particles <45 microns increased reactivity whereas primarily angular-shaped fly ash suffered from reduced workability. The optimal range of workability lay between the 110–150 mm slump, which corresponded with higher strength displayed for each respective precursor fly ash. Higher quantities of aluminum incorporated into the silicate matrix during the reaction process led to improved compressive strengths, illustrated by the formation of reactive aluminosilicate bonds in the range of 800–1000 cm–1 after geopolymerization, which is evidence of a high degree of reaction. In addition, a more negative fly ash zeta potential of the ash was identified as improving the initial deprotonation and overall reactivity of the geopolymer, whereas a less negative zeta potential of the mortar led to increased agglomeration and improved gel development. Following geopolymerization, increases in the quantity of quartz and decreases in moganite correlated with improved compressive strength of the geopolymers. Overall, Loy Yang geopolymers performed better, primarily due to the higher aluminosilicate content than its Yallourn counterpart. The final step was to transition the optimal geopolymer concrete mix designs to producing commercially acceptable bricks. The results showed that the structural integrity of the specimens was reduced in larger batches, indicating that reactivity was reduced, as was compressive strength. It was identified that there was a relationship between heat transfer, curing regimen and structural integrity in a large-volume geopolymer brick application. Geopolymer bricks were successfully produced from the Loy Yang fly ash, which achieved 15 MPa, suitable for application as a structural brick. Further research is required to understand the relationship between the properties of the fly ash, mixing parameters, curing procedures and the overall process of brown coal geopolymer concrete brick application. In particular, optimizing the production process with regard to reducing the curing temperature to ≤80 °C from the current 120 °C and the use of a one-part solid activator to replace the current liquid activator combination of sodium hydroxide and sodium silicate.
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Duży, Patrycja, Izabela Hager, Marta Choińska-Colombel, and Ouali Amiri. "Chloride Diffusion and Mechanical Performances of Geopolymer Concrete with Blended Precursor." In Springer Proceedings in Materials, 220–29. Cham: Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-72955-3_22.
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AbstractGeopolymer concrete is an environment-friendly material and is presently accepted as an alternative to conventional concrete. It utilizes industrial by-products like fly ash and slag to reduce CO2 emissions associated with cement production. Despite being investigated over the decades, the application of geopolymers in construction is still very limited. Most of the research data refer to geopolymer pastes and mortars and their properties, performances, and durability. Although geopolymer concretes are well-accepted in the research community owing to their comparable or even better performances as a cement substitution.In this paper, the precursors for geopolymer concrete preparations are blends of fly ash (FA) and ground granulated blast-furnace slag (GGBFS) in three slag proportions: 5%, 20%, and 35% expressed as a percent of FA mass. The concretes were denominated AAC5, AAC20, and AAC35, respectively. Their basic physical and mechanical characteristics were investigated, as were their transport properties of chloride ions. The ASTM C1556 test was applied to determine the chloride ions’ penetration of the geopolymers. The measurements revealed a strong dependence between chloride penetration through the concrete and the precursor composition.
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Jia, Dechang, Peigang He, Meirong Wang, and Shu Yan. "Introduction." In Geopolymer and Geopolymer Matrix Composites, 1–6. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-9536-3_1.
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Jia, Dechang, Peigang He, Meirong Wang, and Shu Yan. "Geopolymers and Their Matrix Composites: A State-of-the-Art Review." In Geopolymer and Geopolymer Matrix Composites, 7–34. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-9536-3_2.
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Jia, Dechang, Peigang He, Meirong Wang, and Shu Yan. "Geopolymerization Mechanism of Geopolymers." In Geopolymer and Geopolymer Matrix Composites, 35–80. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-9536-3_3.
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Jia, Dechang, Peigang He, Meirong Wang, and Shu Yan. "Graphene-Reinforced Geopolymer Matrix Composites." In Geopolymer and Geopolymer Matrix Composites, 81–129. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-9536-3_4.
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Jia, Dechang, Peigang He, Meirong Wang, and Shu Yan. "Particles-Reinforced Geopolymer Matrix Composites." In Geopolymer and Geopolymer Matrix Composites, 131–77. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-9536-3_5.
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Jia, Dechang, Peigang He, Meirong Wang, and Shu Yan. "Short Carbon Fiber (Csf)-Reinforced Geopolymer Matrix Composites." In Geopolymer and Geopolymer Matrix Composites, 179–241. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-9536-3_6.
Full textConference papers on the topic "Geopolymer"
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Khalifeh, Mahmoud, Arild Saasen, Helge Hodne, Rune Godøy, and Torbjørn Vrålstad. "Geopolymers As an Alternative for Oil Well Cementing Applications: A Review of Advantages and Concerns." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-61227.
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Geopolymers, being inorganic polymers created from rock sources, were evaluated as an alternative to Portland cement. To evaluate their usability some properties of a selected geopolymer were measured and compared with those from a neat class G Portland cement. The geopolymeric slurries showed a non-Newtonian viscosity behavior with a measurable, albeit low, yield stress. The pumpability measurements using atmospheric and pressurized consistometer showed an adequate set profile for both the geopolymer and cement sample. Static fluid loss test show that the geopolymeric slurries experienced a lower fluid loss compared to that of the Portland cement. The shrinkage factor for the geopolymers was reduced (expanded) as the downhole temperature was ramped up. The shrinkage of the Portland cement sample proceeded only with a lower rate. Tensile strength of the geopolymers was approximately 5% of their compressive strength; however, this value for Portland cement was approximately 10% of its compressive strength. Finally, shear bond strength of geopolymers would benefit from improvement.
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Khalili, P., M. Khalifeh, and A. Saasen. "The Effect of Drilling Fluid Contamination on the Properties of Granite-Based Geopolymers at Elevated Temperature." In IADC/SPE International Drilling Conference and Exhibition. SPE, 2024. http://dx.doi.org/10.2118/217942-ms.
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Abstract Granite-based geopolymers have shown great potential as viable and sustainable alternatives to fully replace OPC. This article shows the impact of drilling fluid contamination (both water-based and oil-based) on the rheological and mechanical properties of such a geopolymer. The mechanisms involved in contamination are also explored. The maximum contamination intake before geopolymers lose most of their strength is investigated. Optimized granite-based geopolymer is mixed with varying volumes of a typical water-based drilling fluid (5% and 10%). The resulting mixture is cured under bottom hole static temperatures (BHST) of 70℃ and 13.79 MPa pressure to simulate production casing conditions. Compressive and tensile strengths of the cured contaminated geopolymer are measured after 1, 3, and 7 days. The early strength is evaluated using the Ultrasonic Cement Analyzer (UCA). The impact of the drilling fluid on the geopolymer's microstructure is analyzed using Scanning Electron Microscopy (SEM). The results show that the geopolymer is more sensitive to the Water-Based Mud (WBM), and slurry does not develop strength after 1 day if contaminated with higher than 10% WBM. This behavior is due to geopolymerization reaction in which water remains in the system, unlike the consumption of water in OPC due to hydration. Particle sedimentation is also increased as more contamination is introduced into the geopolymer. SEM images show that after contamination with OBM, geopolymer slurry becomes an oil in water emulsion which leaves dispersed oil in pores throughout the sample after the setting phase.
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Moukannaa, Samira, Ali Nazari, Ali Bagheri, Mohamed Loutou, and Rachid Hakkou. "Thermal resistance of alkaline fused phosphate sludge-based geopolymer mortar." In The 13th international scientific conference “Modern Building Materials, Structures and Techniques”. Vilnius Gediminas Technical University, 2019. http://dx.doi.org/10.3846/mbmst.2019.073.
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The present study investigates the thermal behaviour of phosphate sludge-based geopolymers. Phosphate sludge which is a by-product from phosphate beneficiation processes was activated using the alkaline fusion method to improve the geopolymer activity of this material. Then, the mechanical properties as well as the thermal behaviour of the resulted geopolymer mortar were studied. The effect of sodium hydroxide addition and fusion temperature on the mechanical properties and the thermal behaviour of the geopolymers were assessed using compressive strength tests before and after thermal shock cycles at different temperatures (350, 500, 650 °C). The mineralogical composition of the fused materials was investigated using XRD measurement and the microstructure of the geopolymer mortars was studied using FTIR. The obtained results showed that NaOH content as well as the temperature of fusion are essential parameters controlling the structure and the strength of the developed geopolymeric gel. Exposure to elevated temperatures up to 650 °C induces a decrease in compressive strength between 58 and 71%. However, a further increase in the temperature of exposure till 800 °C induces a development of compressive strength. Overall, geopolymers with good compressive strength up to 40 MPa could be synthesized in the optimum conditions of fusion: 10% of NaOH and 550 °C.
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"The effect of glass fiber length on compressive and flexural strength of reinforced geopolymer." In Sustainable Processes and Clean Energy Transition. Materials Research Forum LLC, 2023. http://dx.doi.org/10.21741/9781644902516-35.
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Abstract. The use of fly ash in the development of geopolymers is considerably practical in minimizing landfills. In addition, to preserve the environment, this approach may also help converting waste material to profitable returns. Currently, geopolymers are used in numerous applications owing to their properties that are comparable as the conventional material of Ordinary Portland Cement (OPC). A few advantageous properties of the geopolymers included resistant to acid, fast setting, high compressive strength and produce low carbon dioxide gas to the atmosphere. However, chemical interaction of raw aluminosilicates reactive precursor with an aqueous alkaline solution during synthesis process has commonly produced a porous geopolymer, which gives the limitation to the geopolymer performance. This weakness may be recovered by implementing fiber reinforcement to improve the properties and reduce the number of internal pores of the geopolymer. This study evaluates the enhancement recorded in geopolymer properties prior to addition of glass fiber into geopolymer matrix. The results of adhesion, flexural and compressive strength of geopolymer significantly increased by addition of glass fiber.
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Sazali, Y. A., L. Riyanto, M. S. Ebining, S. H. Rahman, N. N. Zulkarnain, A. K. Kumar, and C. H. Lau. "Geopolymer for Oilfield Application: Scaling up Laboratory Test to Yard Test." In SPE Annual Technical Conference and Exhibition. SPE, 2023. http://dx.doi.org/10.2118/215163-ms.
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Abstract The present paper describes applicability of geopolymers to oilfield use. As a completely new system in oilfield, one of the main concerns about geopolymer was compatibility with oilfield equipment. It is known that geopolymer system differs from a conventional cement by a composition of base fluid and a mixing order which leads to a question of capability of existing cementing equipment to handle the geopolymer slurries. In order to validate mixability and pumpability of geopolymer slurry, a yard test had been conducted in order to test geopolymer formulations with two densities, 15 and 16.5 pgg. The yard test proved that the geopolymer system could be mixed and pumped using conventional equipment in the batch mixing as well as in the on-the-fly pumping regimes. During the yard test the geopolymer formulations were pumped with a rate up to 6 bbl/min. Results showed that special attention should be paid to a base fluid preparation and HSE aspects of the mixing and pumping process. The articles discuss practical recommendation about geopolymer preparation and pumping. For the first time it was demonstrated that geopolymer systems could be mixed and pumped using conventional cementing equipment. All mixed geopolymer slurries tested according to the API RP 10B standard and demonstrated acceptable properties, including rheology, thickening time, compressive strength and fluid loss. In addition to that the paper suggests the draft of the quality control procedure for geopolymers used in oilfield.
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Fang, C., Y. Elakneswaran, X. Niu, and N. Hiroyosi. "Interaction of organic liquid with metakaolin-based geopolymer." In International Symposium on Earth Resources Management & Environment - ISERME 2023. Department of Earth Resources Engineering, 2023. http://dx.doi.org/10.31705/iserme.2023.18.
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In recent years, there has been growing interest in geopolymer cement as a more sustainable alternative to traditional concrete. Metakaolin-based geopolymers have a high capacity to immobilise radioactive cations such as Cs+ and Sr2+ via an ion exchange mechanism. In the meantime, the geopolymer has a high potential to solidify organic liquid waste and has been considered for developing porosity-controlled materials. However, the interaction mechanism between organic liquid and metakaolin-based geopolymer has not been fully understood. In this study, the appropriate control of organic liquid in the geopolymer has been studied. Firstly, alkali-activated solution (K2O:SiO2:H2O molar ratio of 1:1:13) was mixed with the lubricant (FBK Turbine 32) and cationic surfactant (CTAB) to form an emulsion. Then metakaolin-based (Sobueclay) geopolymers were synthesised in the emulsion (Al: Si molar ratio of 1:1). The interaction mechanism between the oil with emulsion and geopolymer (with or without surfactant) was evaluated using the zeta potential, paste slump flow, SEM, and compressive strength. The metakaolin-based geopolymer could not solidify the oil. However, the geopolymer can successfully solidify oil content with the help of a surfactant that changes the surface of the oil from negative to positive, allowing it to interact with the opposing surface of the geopolymer. However, the compressive strength of the resulting composite decreased as the oil content increased due to an increase in porosity, and as the hydration products filled the pores over time, the strength increased. These findings suggest that geopolymer could be a promising solution for solidifying oil. However, careful consideration must be given to the porosity induced by the presence of oil to ensure that the resulting composite has sufficient strength for its intended application.
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Meade, Mark, Yeukayi Nenjerama, Chris Parton, Veronica Richter McDonald, Nathan Fischer, Saurabh Kapoor, Andrey Yakovlev, et al. "First Global Implementation of Geopolymer in Primary Casing Cementing." In Offshore Technology Conference. OTC, 2023. http://dx.doi.org/10.4043/32218-ms.
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Abstract Portland cements are integral components in the oilfield well construction process; however, the confluence of various business drivers have created the need to find sustainable alternatives materials. Geopolymers, already well known in traditional construction industries, show promise as alternatives to Portland cement in oilfield wells. Yet, successfully moving geopolymers from a concept in the laboratory to execution at the wellsite remains to be established. This paper presents evaluation of geopolymer cementing for use in oil and gas wells, specifically the primary cementing of liner strings in the Permian Basin. To evaluate geopolymer cementing for oil and gas well construction, a field example project was divided into four phases: development of robust slurry design in the laboratory, confirmation of compatibility with oilfield equipment, scalability for safe execution in the field, and validation through post-job evaluation techniques. The laboratory work included an engineered, innovative approach to chemistry to obtain a slurry matching and exceeding performance of Portland cement−based designs. Yard trials were performed to verify compatibility of geopolymers with industry-standard oilfield cementing equipment. The geopolymer-based designs were then scaled up to meet typical cementing job volumes and executed at the wellsite without deviating from conventional operating procedures. Post-job evaluation techniques to validate the placement included pressure matching and cement bond logs. Results have shown that for primary cementing applications, geopolymers can be an effective alternative to Portland cements. This case demonstrates that geopolymer cementing was able to fit into the oilfield cementing workflow without major changes to job design process, onsite execution, or post-job evaluation. Post-job pressure match of hydraulic simulations versus recorded pressure during job execution confirmed proper placement and conventional sonic and ultrasonic cement bond logging tools were able to confirm the presence of geopolymers within the wellbore providing further assurance. Introduction of geopolymer cementing requires the adaptation of innovative chemistry into the slurry design and consequently sourcing of materials typically not used in Portland cement blends. Additionally, attention to quality control of raw materials is required to ensure consistency of performance. Overall, geopolymer cementing can be successfully implemented into oilfield primary casing cementing applications using the existing infrastructure that has evolved from the historic use of Portland cement. Geopolymer cementing offers a unique opportunity for the oilfield industry to decrease CO2 emissions related to well construction and reduce dependence on the constrained supply of Portland cements. The case of cementing intermediate liner in the Permian Basin validates the scalability of the concept from inception in the laboratory to wellsite execution.
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Omran, Mohamed, Mahmoud Khalifeh, and Arild Saasen. "Influence of Activators and Admixtures on Rheology of Geopolymer Slurries for Well Cementing Applications." In SPE Asia Pacific Oil & Gas Conference and Exhibition. SPE, 2022. http://dx.doi.org/10.2118/210698-ms.
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Abstract Geopolymers are considered an alternative to Ordinary Portland Cement due to various reasons regarding some of its shortcomings and the high carbon dioxide footprint associated with its production. Superplasticizers are admixtures that plasticize and fluidize the cementitious slurry by means of steric electrostatic mechanisms that apply repulsion forces between the slurry particles. They are commonly used to improve the workability of cement and geopolymer pastes. However, the most developed superplasticizers are for Ordinary Portland cement. Electrokinetic potential measurements of the ingredients can be used in the evaluation of superplasticizers. Therefore, the effect of the utilization of two hardeners and the effect of the electro-kinetic potential of four admixtures, on the rheological properties of a rock-based geopolymer slurry are presented. These four admixtures are examined to investigate their applicability to being superplasticizers for conventional geopolymers. The results show that naphthalene-based admixtures could be considered effective superplasticizers for the rock-based geopolymer slurry. Although they reduce the slurry's yield stress and API gel strength by showing the highest absolute zeta potential value, the viscous behaviour of the geopolymer slurries showed an increase. Hence, electro-kinetic potential measurements could be used to evaluate the applicability and performance of the admixtures on the rheological properties of the geopolymer slurry.
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Salehi, Saeed. "Applicability of Geopolymer Materials for Well P&A Applications." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-62351.
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Previous research on application of geopolymers in oil/gas wells is mainly unsuccessful due to failure to achieve a reasonable thickening time. This study presents geopolymer composite mixtures that have high compressive and shear bond strength, enhanceed thickening time, high durability, and reasonable shrinkage. Class F fly ash geopolymers are used for developing samples with different mix designs in this work. Class H Portland cement is used as a controller on all the tests conducted in this work. Tests conducted in this research include: unconfined compressive strength (UCS), shear bond strength, thickening time, and durability tests. Results indicate temperature as a crucial factor affecting the thickening time of geopolymer mix slurry. More than four hours thickening time is achieved by optimizing mix design and applying a developed mix of superplasticizer and retarder. UCS testing indicates a high compressive strength after one and fourteen days of curing for geopolymer mixtures. More than 6000 psi strength is achieved in long term (28 days curing). This indicates strength gained over time, for geopolymer mixture, where strength retrogression effects are observed for Portland cements. Results also reveal higher shear bond strength for Geopolymer mix, which can better tolerate de-bonding issues. Additionally, more ductile material behavior and higher fracture toughness, were observed for optimum geopolymer mixes. Final observations confirm applicability of these materials for oil and gas well cementing with circulating temperatures up to 300°F.
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Adjei, Stephen, Salaheldin Elkatatny, Wilberforce Nkrumah Aggrey, and Yasmin Abdelraouf. "Extended Abstract: The Feasibility of Using Geopolymer in Oil-Well Cementing: A Review." In International Petroleum Technology Conference. IPTC, 2022. http://dx.doi.org/10.2523/iptc-22130-ms.
Full textAbstract:
Abstract Over the years, various cementitious materials have been investigated as a substitute for conventional cement. One example of these materials is geopolymer, a binder developed when an alkaline solution is used to activate materials containing alumina and silica. The use of this material is well established in the construction industry. In oil-well cementing, its feasibility is currently being investigated. An extensive survey on the various geopolymer studies has been conducted. The goal is to present a manuscript containing a summary of these studies. This will help researchers merge the knowledge acquired going forward. The study showed that the application of geopolymer in acidic and saline conditions, and in well plugging and abandonment operations. Additionally, geopolymer-mud compatibility and the impact of temperature on geopolymer systems have also been studied. In general, geopolymer systems show better performance, overcoming the limitations of the OPC systems. For instance, the geopolymer is more suited for CO2 sequestrations wells as it does not undergo a carbonation reaction which would result in degradation. Furthermore, geopolymers have superior performance in highly saline conditions and besides their compatibility with mud, a geopolymer-mud combination produces cementitious systems with enhanced properties.
Reports on the topic "Geopolymer"
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Al-Chaar, Ghassan, Allison Brandvold, Andrij Kozych, and William Mendoza. 4D printing structures for extreme temperatures using metakaolin based geopolymers. Engineer Research and Development Center (U.S.), April 2023. http://dx.doi.org/10.21079/11681/46750.
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Geopolymers (GPs) are a class of amorphous, aluminosilicate-based ceramics that cure at room temperature. GPs are formed by mixing an aluminosilicate source, which is metakaolin in this case, with an alkali activator solution, which can be either sodium or potassium water glass. GPs have attracted interest for use in structural applications over the past few decades because they have superior mechanical properties to ordinary Portland cement (OPC). Additionally, they can tolerate much higher temperatures and produce a fraction of the CO₂ compared to OPC. This project aims to develop geopolymer composites for 4D printing (the fourth dimension being time) and test their mechanical properties. Rheology and the effects of curing in ambient conditions will be evaluated for fresh geopolymer. Freeze-thaw resistance will be evaluated on potentially printable composites for extreme temperature resistance, etc.
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Stoddard, Damien, Paul G. Allison, Robert D. Moser, and Wayne Hodo. Characterization of Metakaolin-Based Geopolymer (Briefing chart). Fort Belvoir, VA: Defense Technical Information Center, July 2014. http://dx.doi.org/10.21236/ada634115.
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Al-Chaar, Ghassan, Peter Stynoski, Matthew Landi, and Marion Banko. Method of construction for geopolymer soil stabilized platforms. Construction Engineering Research Laboratory (U.S.), January 2018. http://dx.doi.org/10.21079/11681/26029.
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Gong, W. L., Werner Lutz, and Ian L. Pegg. DuraLith Alkali-Aluminosilicate Geopolymer Waste Form Testing for Hanford Secondary Waste. Office of Scientific and Technical Information (OSTI), July 2011. http://dx.doi.org/10.2172/1027180.
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Nikolov, Aleksandar. Characterization of Geopolymer Based on Fayalite Waste and Metakaolin with Standard Consistence. "Prof. Marin Drinov" Publishing House of Bulgarian Academy of Sciences, October 2021. http://dx.doi.org/10.7546/crabs.2021.10.05.
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Pierce, Eric M., Kirk J. Cantrell, Joseph H. Westsik, Kent E. Parker, Wooyong Um, Michelle M. Valenta, and R. Jeffrey Serne. Secondary Waste Form Screening Test Results?Cast Stone and Alkali Alumino-Silicate Geopolymer. Office of Scientific and Technical Information (OSTI), June 2010. http://dx.doi.org/10.2172/989447.
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Srubar, Wil, Claire White, Christine Pu, and Mohammad Matar. Geopolymer Cements: Resistance-Engineered Sewer Infrastructure for Longevity using Innovative, Energy-efficient, Synthesis Techniques (RESILIENT). Office of Scientific and Technical Information (OSTI), August 2023. http://dx.doi.org/10.2172/1997265.
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Zhao, Youyang, Thomas Viverito, Ryan Bowers, Chase Kimbal, Tunahan Aytas, and Elsa Olivetti. An Innovative Design of High-Temperature, Sensible Molten Salt Thermal Energy Storage Systems With Geopolymer Insulation. Office of Scientific and Technical Information (OSTI), January 2024. http://dx.doi.org/10.2172/2280670.
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Pires, Richard P., Joseph H. Westsik, R. Jeffrey Serne, Shas V. Mattigod, Elizabeth C. Golovich, Michelle M. Valenta, and Kent E. Parker. Secondary Waste Form Screening Test Results—THOR® Fluidized Bed Steam Reforming Product in a Geopolymer Matrix. Office of Scientific and Technical Information (OSTI), July 2011. http://dx.doi.org/10.2172/1027188.
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Wilson, Clint, Jaclyn Mathis, Lawrence Clark, and Anthony Delgado-Connor. Geopolymer nanoceramic mortar liner system for corrosion protection and rehabilitation of stormwater piping : final report on Project F14-AR05. Construction Engineering Research Laboratory (U.S.), August 2017. http://dx.doi.org/10.21079/11681/22787.
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